单文件：html
<!DOCTYPE html>
<html>
<head>
<title>响应式基础</title>
</head>
<body>
<div id="app" >
<!-- dynamic parameter:同样在指令参数上也可以使用一个 JavaScript 表达式，需要包含在一对方括号内： -->
</div>
<!-- 引入Vue.js -->
<script type="module">
import { createApp,ref } from "https://unpkg.com/vue@3/dist/vue.esm-browser.js"
const count = ref(0)
console.log(count) // { value: 0 }
console.log(count.value) // 0
createApp({
data(){
return {
}
}
}).mount('#app')
</script>
</body>
</html>组合文件
html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div id="app"></div>
<script type="module">
import {createApp, ref} from "https://unpkg.com/vue@3/dist/vue.esm-browser.js"
import count from './reactive.js'
createApp(count).mount('#app')
</script>
</body>
</html>reactive.js
import { ref } from 'https://unpkg.com/vue@3/dist/vue.esm-browser.js'
export default {
// `setup` 是一个特殊的钩子，专门用于组合式 API。
setup() {
const count = ref(0)
// 将 ref 暴露给模板
return {
count
}
}
}
